“The average Italian makes $26,700 a year, however those in the more prosperous north make almost $40,000.” — unknown
This pretty unique sentence that should be cited. One may even wish to know the source of these facts, or perhaps the year. However, a quick Google search for the exact phrase shows that it appears in a list of “fun facts” on dozens of websites, and I have not yet found one that cited it.
More than ever, we need to teach students how to consume information critically and cite sources.